Cut the meat into large cubes, about 3-4 cm/ 1.5 inch. Dry very well with kitchen paper. Set aside.
Chop onions and garlic and set them aside separately from the meat. Chop the bacon.
Heat a Dutch oven or another heavy-bottomed pan. Add bacon. There is no need for oil, the bacon will render its fat. Cook for 2 minutes, stirring.
Add onions and garlic, stir well and cook for another 3 minutes. Add tomato paste, stir well for 1 minute.
Deglaze the pan with the red wine, scraping the bottom as well, for about 1 minute. Pour the contents of the pan into the slow cooker.
Wipe the pan clean with kitchen paper, be careful, it’s hot!
Place one batch of the meat cubes in a bowl, add a little of the flour, and toss well.
Heat 1 tablespoon oil in the Dutch oven. Fry the meat pieces in 2 or 3 batches until golden, about 3-4 minutes per batch, turning the meat a few times in between. Only flour the next batch of meat just before it goes to the pan and add a little more of the oil between the batches. Don’t overcrowd the pan or the meat will stew instead of searing. Transfer all the meat to the slow cooker.
Peel the potatoes and the carrots. Cut them into larger chunks. Place in the slow cooker.
Add thyme, rosemary, 2-3 bay leaves, salt, pepper, and stock. The amount of salt you need depends on the stock (Note 4).
Turn on the slow cooker and cook for about 6 hours on high and about 8 hours on low.
Once the meat and the potatoes are as tender as you want them to be, mix the corn starch and the water to obtain a thick paste. Whisk the slurry into the gravy. If the slow cooker is on high, the sauce will thicken almost instantly. If not, cover the pot again and simmer for about 5-10 minutes more until the sauce thickens.
Adjust the taste with salt, pepper, Worcestershire sauce, and vinegar.